This invention relates to an apparatus for tightening and loosening jaws of a chuck; more particularly, it relates to a device for easing impact and abrasion on an operator's hand in such an apparatus when the chuck is tightened or loosened about a work tool by motorized operation of the machine spindle.
There are, in the prior art, many examples of keyless chucks. For example, there is U.S. patent application Ser. No. 179,359, filed Aug. 18, 1980 by Clary. There are also U.S. Pat. Nos. 4,277,074 of Kilberis, 3,506,277 of Harms, and 2,684,856 of Stoner. The above and other prior art exhibit one undesirable characteristic which is avoided in the instant invention. All the prior art devices provide for an operator's grasping of a collar and sliding the same to bring about an engagement between stationary and rotating teeth, which teeth induce a motion of the sleeve when the chuck locks about the work tool, which motion may tear and abrade an operator's hand. What is required is an arrangement which protects an operator's hand from the tearing and abrading motion normally encountered. Ideally, this arrangement must be extremely compact so as not to appreciably enlarge the chuck and must be capable of economical manufacture.